Science·What on Earth?

How Indigenous 'cultural burns' can replenish our forests

In this week's issue of our environment newsletter, we look at how Indigenous fire practices can help us avoid high-intensity wildfires and how plastic pellets are ending up in the Great Lakes.

Also: The wrath of the climate strikers

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(Sködt McNalty/CBC)

Hello, Earthlings! This is our weekly newsletter on all things environmental, where we highlight trends and solutions that are moving us to a more sustainable world. (Sign up here to get it in your inbox every Thursday.)

This week:

  • How Indigenous 'cultural burns' can replenish our forests
  • The wrath of the climate strikers
  • Industrial plastic is spilling into the Great Lakes, and no one's regulating it, experts warn

How Indigenous 'cultural burns' can replenish our forests

(Sködt McNalty/CBC)

For more than a century, Canadian wildfire suppression has stuck to the hit-it-hard-hit-it-fast motto — and has been highly effective in snuffing out the flames. 

The paradox, said Prof. Lori Daniels, who specializes in wildfire and forest ecology at the University of British Columbia, is that we've been so good at putting out every fire possible that it has led to overly dense forests and a buildup of burnable material like branches and dry vegetation. 

If sparked in the summer heat, these "ladder fuels" piggyback the flames up tree trunks and engulf the crown, resulting in high-intensity fires like those in Western Canada this year.

But overdrive isn't fire's only speed. In fact, when burning in a lower gear, the environmental benefits of fires in forested areas can be bountiful.

"If you want to cleanse the land, if you want to give back to the land, you burn it," said Daniels.

Low-intensity burns, also known as cultural burns, have been lit purposefully since time immemorial by Indigenous firekeepers around the globe to rebalance ecosystems. When woods are groomed this way by burns, Daniels said, the chances of a crown fire occurring in the hotter months decreases.

Brenden Mercer, a forest field management liaison for First Nations' Emergency Services Society of British Columbia, said cultural burns are traditionally carried out in the spring or fall, when mild conditions and favourable winds set the stage.

Mercer knows stories of firekeepers saying a prayer and introducing fire to the landscape from a smoking tree conk. The slow-moving flames engulf litter and dead materials, such as sticks and pine cones, and then flicker up to devour the intermediate saplings.

(Sködt McNalty/CBC)

The heat creeps down, too, cooking bits of the spongy duff layer, where dormant, fire-adapted seeds — which could be waiting in the soil for decades — pop open.

By timing the cultural burn correctly, the fire extinguishes at the snow line, said Mercer. As the snow continues to melt, firekeepers return to light as often as necessary until they've burned to the top of the hill.

Post-burn, a thinned-out and spacious forest breathes new life. According to Mercer and Daniels, regeneration begins. Wild grasses bounce back with a vengeance. Old shrubs sprout new shoots. Native and medicinal plants bask in the sun. Elk, bison and big-horned sheep return to graze. Insects munch on fresh broadleaf plants and berry bushes. 

Importantly, big trees grow bigger and develop thicker bark, becoming more resistant to surface fires. The canopy stretches out to provide habitat for insects, birds and animals. Down the tree, carbon sinks into the soil.

Mercer said that before colonial practices took over, Indigenous firekeepers treated dry forests, like those of B.C.'s Interior, with low-intensity burns every five to 25 years. Daniels's research of fire evidence in tree rings corroborates this history.

Brady Highway, a project manager of wildfire strategy for the Ottawa-based Indigenous Leadership Initiative, fought his first fire at the age of 15, and has fought hundreds since. He said today it's very rare that Indigenous people can actually carry out a cultural burn because of how hard it is to get permits. 

"When it comes to prescribed fire, we must allow communities to revitalize those practices," said Highway, whose grandmother instilled in him the obligation to look after the land. "The stakes couldn't be higher. What we're talking about is the land, and without the land, we have nothing."

As Mercer looked out across the thousands of charred hectares in Lytton, B.C., earlier this year, he noted some of the consequences of a high-intensity fire: dead trees, nutrient-depleted soil and a disruption of carbon sequestration. 

Mercer's master thesis focused on carbon storage and ecosystem management. His research found that prescribed burns promote carbon storage by burning off smaller trees and allowing big trees, which pull much more carbon from the atmosphere than saplings, to grow bigger.

High-intensity forest fires release a huge amount of carbon into the air, but even after the smoke has cleared, Mercer said the decaying forests lose their ability to absorb carbon, and, as the matter breaks down, the dead forest continues to release carbon into the air.

When the 1874 Bush Fire Act passed in B.C., Mercer said colonial practices took over and First Nations people were essentially banned from lighting cultural burns. He said without consistent burns treating forests for more than a century, wildfires today "can just run and run." 

He said the American public service announcements featuring Smokey the Bear, which were launched in the 1940s, are responsible for skewing the issue. 

"Some communities just are so afraid of fire … due to the propaganda that Smokey the Bear was pumping out for years, where fires are bad," Mercer said. "Some people just have that so ingrained, that all fires are bad. It's definitely not the truth. It's just high-severity fires that are bad."

Mercer said wildfire "needs to be applied back to the landscape in a meaningful fashion. The only realistic way to do that is to empower First Nations to be firekeepers on the landscape, and give them all the tools, the funding, all the resources that they need to be true partners and manage the landscape in partnership with everybody else."

Fenn Mayes

Reader feedback

Last week, Rachel Sanders wrote about the efforts of some Canadian high school students to enhance the climate change content in the curriculum.

Marjorie Bruhmuller: "Thanks Rachel Sanders! [Climate change] should be a major part of education. It might give kids a more hopeful-looking future if they can participate and understand what's at stake, and what they can do to change things."

Elizabeth Webster: "Kudos and gratitude to the students who are speaking up in favour of climate change education in their schools. I teach in a large suburban high school north of Chicago, Illinois. I'm scared to bring it up with my students, worried that I'll get backlash from denier parents and students. It's truly a legitimate concern. Let's hope that the administrative teams from Canadian schools will stand firmly behind climate change curriculum."

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Old issues of What on Earth? are right here.

There's also a radio show and podcast! Climate change amplifies the threats caribou face across Canada. This week, What On Earth host Laura Lynch hears how keeping CO2 out of the air and in the ground is part of the solution for caribou and a warming world. What On Earth airs Sunday at 12:30 p.m., 1 p.m. in Newfoundland. Subscribe on your favourite podcast app or hear it on demand at CBC Listen.

The Big Picture: The wrath of the climate strikers

Last Friday marked the return of worldwide climate strikes, which began in March 2019 and had been growing in number before the arrival of COVID-19 made such large gatherings unsustainable. A month out from the UN COP26 climate summit in Glasgow, Scotland, activists and students around the globe came out in force last week to demand more action from governments in fighting climate change. While there was an element of hope in the demonstrations, the most visible climate striker, Greta Thunberg, has been sounding a note of pessimism — if not outright disgust — at the level of institutional engagement with the problem of a warming world. Speaking at a pre-COP youth summit in Milan, Italy, earlier this week, Thunberg called out the virtue signalling of many world leaders. "Build back better. Blah, blah, blah. Green economy. Blah, blah, blah. Net zero by 2050. Blah, blah, blah. This is all we hear from our so-called leaders. Words that sound great but so far have not led to action. Our hopes and ambitions drown in their empty promises." Fellow activist Vanessa Nakate (photo below), a 24-year-old from Uganda, scolded rich nations for their unmet financial pledges to help the countries most vulnerable to the effects of climate change, such as those in southeast Asia and Africa. "Funds were promised by 2020, and we are still waiting," Nakate said. "No more empty conferences. It's time to show us the money."

(Miguel Medina/AFP via Getty Images))

Hot and bothered: Provocative ideas from around the web

Industrial plastic is spilling into the Great Lakes, and no one's regulating it, experts warn

(Synthetic Collective)

As Torontonians flocked to the Lake Ontario waterfront to swim, paddle and generally escape pandemic isolation, Chelsea Rochman's students at the University of Toronto were throwing plastic bottles with GPS trackers into the water.

The team's goal is to track trash that ends up in the lake, to figure out where it accumulates in the water and where it's coming from in the first place.

The research program is part of the larger Great Lakes Plastics Cleanup, supported by various government agencies and private organizations. There are now Seabins installed at marinas across the Great Lakes region to help tackle the plastics problem.

Using information from the tracking bottles, Rochman's team chose spots to put in Seabins — stationary cleaning machines that suck in water all day and trap any garbage and debris — at marinas along the waterfront. They are emptied daily, and the debris collected in them is examined to ferret out what kinds of trash is getting into the lake.

The waste includes well-known single-use culprits like takeout containers and clear plastic packaging, as well as something that gets less attention:  pre-production pellets. 

"They're the tiny little pellets that are later melted down into plastic and different plastic products," Rochman said. 

An estimated 10,000 tonnes of plastic waste are getting into the Great Lakes every year, threatening one of the planet's largest reservoirs of freshwater, which supports nearly 50 million people in Canada and the U.S. 

While the plastics industry says it's working on the problem through its own initiatives, advocates say there's a lack of government regulations to address this kind of pollution.

In 2020, Rochman's Tagging Trash team collected about 85,000 pieces of microplastics (smaller than five millimetres), along with larger pieces of plastic, in the Toronto harbour. About 13 per cent of the microplastics they were capturing were pre-production pellets, which can fly off transport vehicles or facilities and end up in the water.

Rochman said "we are now working with industry to try to make sure that they capture them at the source so they don't come down into the lake."

Last year, the Chemistry Industry Association of Canada (CIAC), which represents about 75 plastics companies, signed onto Operation Clean Sweep, a global program to prevent plastic materials from industrial operations ending up in lakes and rivers.

"We're working with our members to make sure they're putting in place the leading technology, policies and practices and training of their own staff to ensure that these plastic pellets don't end up in the environment," said Elana Mantagaris, vice-president of the plastics division at CIAC.

Yannick Beaudoin, the director of innovation at the David Suzuki Foundation in Toronto, said that while industry-led initiatives like Operation Clean Sweep help, they do not solve the whole problem. Government intervention, along with pressure from consumers, is necessary to cut down on these plastics and keep them out of the lake. 

But figuring out which government agency or law should be involved can be a challenge. Beaudoin said the issue crosses jurisdictional boundaries, with the federal government in charge of protecting transboundary waters as well as regulating chemicals and products that are toxic. However, it remains unclear if pre-production pellets are covered.

Provincial governments in theory have even more power over environmental protection, but Beaudoin said enforcement related to pre-production pellets is simply not applied.

Environment and Climate Change Canada referred CBC to its actions on achieving zero plastic waste by 2030. That effort is focused on single-use plastic products and "working with provinces and territories to make producers responsible for the plastic waste that their products generate." 

The Ontario Ministry of the Environment, Conservation and Parks said that as part of a pilot project, its York Durham District Office is "undertaking inspections of plastics-based industries (manufacturers, recyclers, processors) in York Region aimed at encouraging the use of existing best management practices to reduce discharges to the natural environment."

The statement also said this work "will engage plastics-based industries in order to increase awareness of plastic pellet and scrap losses to waters, assess current industry control practices and identify industry processes that result in plastic pollution."

Across the border in the United States, a bill was introduced this year to address pre-production pellets. The Plastic Pellet Free Waters Act will require the U.S. Environmental Protection Administration to prohibit the discharge of these pellets into waterways from industry and transport sources. The bill is making its way through Congress.

"If you had an oil spill somewhere around here, you'd have to call a very specific government hotline and you have to get a process going, because an oil spill is something that we deem quite visibly as toxic," said Beaudoin.

"Well, plastic pellets are oil. They're just a solid version of it. Why aren't we reacting in the same way?"

Inayat Singh and Alice Hopton

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Editor: Andre Mayer | Logo design: Sködt McNalty

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